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April 29, 1958 H. M. DUsTlN ETAL DIGITAL AcTUAToR CLUTCH MECHANISM 3Sheets-Sheet l Filed Nov. 29, 1954 alla.:

[aule/ze E Reyna/ds.

vBY una April 29, 1958 H. M. DusTlN ETAL 2,832,540

DIGITAL ACTUATOR CLUTCH MECHANISM Filed Nov. 29, 1954 5 Sheets-Sheet 2FlEgE INVENToR` Han/am f?! 17am/z. [age/7e E. Hayao/afs.

April 29, 1958A H. M. DusTIN ETAL A2,832,540

DIGITAL ACTUATOR CLUTCH MECHANISM Filed Nov. 29, 1954 5 Sheets-Sheet 5FLIEJEI- mvENToRs Han/mf M. us f/f?. Eugene E. Reyna/afs.

BY www@ United States Patent O rrd DIGITAL ACTUATR CLUTCH MECHANISMHoward M. Dustin, Alameda, and Eugene E. Reynolds, Richmond, Calif.,assignors to Marchant Calculators, Inc., a corporation of CaliforniaApplication November 29, 1954, Serial No. 471,694

Claims. (Cl. 2255-49) The present invention relates to calculatingmachines and more particularly concerns digital actuating means for thenumeral wheels of an accumulator register.

The present invention is disclosed as embodied in a ten key calculatingmachine of the general type shown in the patent application Serial No.275,259, tiled March 7, 1952, now Patent No. 2,702,668, issued Feb. 22,1955, and with the exception of the actuating means and related actuatorcontrol devices, the two machines are identical.

A ten key keyboard is provided for entry of selected values into theplural order pin carriage. The depression of any value entry key 1 to 9is effective, through the intermediary of the single order entry device,to eject one of nine differentially arranged pins in each respectiveorder of the pin carriage. A tenth pin, one of which is provided in eachorder and referred to hereinafter as the end pin, is ejected at the sametime that one of the nine value pins 1-9 is ejected; thus, in each orderin which a value is entered, two pins are ejected. These two pinscontrol the engagement and disengagement of a numeral wheel clutch, oneof which is permanently associated with each numeral wheel. Theydepression of the 0 key merely shifts the single order value entrydevice relative to the pin carriage without ejecting any of the pins.

During the value entering operation, the pin carriage remains alignedwith the leftmost, or highest orders of the numeral wheel clutches.Therefore, at the end of the value entering operation, .the pin carriagestands in a position to control the entry of a selected value into thehighest orders of the register, or alternatively the pin carriage may beshifted to any position relative to the register before numeral wheelactuation is begun. According to the previously mentioned patent, thepin carriage may be shifted under control of a decimal key and relatedkdevices to a position of decimal alignment with a decimal point in theaccumulator register. The present invention, however, is not concernedwith the decimal and shift control devices and further mention thereofis believed unnecessary, it being sufficient to point out that, in anyshifted position of the pin carriage, the two pins which are ejected ineach order control the engagement and disengagement of a numeral wheelclutch currently aligned therewith.

A main object is to provide animproved numeral wheel actuator clutchwhich operates dependably at high speeds of rotation.

Another object is to engage and disengage a numeral wheel actuatorclutch by means of two respective control devices.

Still another object is to provide a unitary clutch engaging anddisengaging control means for a reversible numeral wheel clutch in whichthe means for engaging and disengaging the clutch in one direction ofrotation are reversed in function during rotation of the clutch in theother direction.

A further object is to provide improved means which` are operable toprevent overthrow of the numeral wheels when their respective clutchesare disengaged, such overthrow preventing means being operable undercontrol of the clutch disengaging means in one direction of rotation ofthe clutch and being operable under control of a cyclically operablemeans during rotation of the clutch in the other direction.

Other objects and advantages of the invention will become apparent fromthe following description when read in conjunction with the accompanyingdrawings in which:

Fig. 1 is a right side view in section showing a calculating machine inwhich the present invention s embodied.

Fig. 2 is an exploded projection as viewed from the left front of themachine, showing a numeral wheel actuator clutch. v

Figs. 3, 4, 5 and 6 are left side views showing the actuator clutch andnon-overthrow mechanism in progressive stages of operation.

Fig. 7 is a right side view showing a portion of the value enteringmechanism.

Fig. 8 is a left side view of a portion of the control mechanism for thenumeral wheel detent.

Value entry mechanism The value entry mechanism includes ten selectionkeys or' which only the zero" and 9 value entry keys 100 (Fig. l) areshown. Since the depression of each value entry key l to 9 effects entryof a respective value into the pin, or storing carriage, in a similarmanner, only the 9 value key is described and the following descriptionwill serve for all nine value entry keys l to 9. The depression of the 0key merely causes a one order escapement of the single order entrydevice as described hereinafter.

The 9 key 100 (Fig. l) is mounted for up and down sliding movement bysuitable means not shown and is spring urged to its raised position inconventional manner. Depression of the key rocks a bellcrank 109 clocknwise about a fixed pivot 112, thus moving link 113 to the left androcking an arm 116 and a shaft 117 in a counterclockwise direction. Asecond arm (not shown), but spaced apart and similar to arm 116, ismounted on an opposite end of shaft 117. Fixed to these arms on shaft117 is a transverse bail 139 which is rocked with the arms. Bail 139 isone of ten bails 130-139 corresponding to the values 0-9. Depression ofthe keys 0, and 2-9, moves the respective bails 130 and 132-139forwardly of the machine (to the left in Fig. 1). Depression of the lkey moves bail 131 rearwardly of the machine.

Ten bellcranks 140-149 are each pivotally mounted as at 118 (seebellcrank 149) on the single order value entry device 120 which isreferred to hereinafter as a setup carriage. This carriage comprises aU-shaped strip of material mounted for shifting movement relative to astoring carriage 125. The upper left end of the set-up carriage 120carries a roller 121 which is embraced by a channel member 122 fixedwithin the framework of `the machine. The upper rightmost end of theset-up carriage 120 carries a roller bearing hub 123 which is slidableupon a transverse shaft 124. This arrangement provides for transversesliding movement of carriage 120 under the control of an escapementmechanism described hereinafter. During such escapement, the bifurcatedtips of the bellcranks -149 maintain contact with their respective bails130439, thus enabling the keys to rock the bellcranks in any shiftedposition of carriage 120.

The set-up carriage 120 and its bellcranks 140-149 underlies the storingcarriage 125. The storing carriage comprises a pair of U-shaped plates126 and 127 which are maintained in spaced relationship by ordinallyspaced intermediate frame members 179. The upper rightmost ends of theleft and right end frame members 179 (one shown) are connected to rollerbearing hubs 196 which are mounted upon a transverse shaft 197. Theleftmost ends of the frame members 179 each carry a hub 198 which 1smounted upon a transverse shaft 199. Control means are describedhereinafter for shifting the storing carriage along the supportingshafts 197 and 199.

The storing carriage 125 may be of any desired pacity, and in thepresent case is disclosed as an eight order storing carriage. in eachorder thereof, there are nine value pins 1161-169 corresponding to thevalues "1 to "9, and there is also provided a Zero shift lever 160.

. Only the bottom portions of the 1, 2 and 3 pins,

161, .162 and 163 respectively, are shown in Fig. l, thc remainder ofthese pins being broken away to permit the illustration of othermechanisms. The value pins i61-169 are each mounted for up and downsliding move ment in slots cut in the U-shaped plates 126 and 127 of-the storage carriage. Thel pins 161-169 have slow which embrace studs12S fixed to the ordinal frame members 179 for guiding the pins 161-169in their up and down movment. Torsion springs 187 are anchored to thebottom plate 26, and are provided between respective pairs of pins (seepins 167 and 163) to normally hold the pins in the retracted positionshown.

Each of the previously described selection set-up bellcranks 1511-149has a respective ear such as' the ear 14% for the bellcrank lit-9, whichears each underlie a corresponding shoulder on the bottoms of the valuestorage pins 161-169 (see shoulder 159 on pin 169). The 0 bellcrank 1401has an ear 140e which underlies the shift control lever 16d. Thearrangement is such that depression of any value ke l to 9 and theresultant rock- 1ng movement of its bellcrank 141-149 will cause acorresponding pin 161-169 to be moved upwardly where it is locked asdescribed hereinafter.

At the same time that one of the nine value pins 161-169 is ejected, asecond pinv 170, referred to hercinafter as the end pin, is alsoejected. As will become apparent from the description of the actuatorclutches, the end pin cooperates with any one of the ejected value pins1651-169 to control the engagement and disengagement of an actuatorclutch'.

The endpin 170 is formed on the left end of a lever 177 pivoted at 17?to the selection storing carriage, and normally stands` in the full lineposition'shown. The end pin 17'@ is in lateral alignment with the No. 2

value pin 152 (not shown) and is raised to the dotted line position whenone of the pins 161-169 is raised. Referring first to. theNo. l and No.2 value pins 16Ev yand 162, these pins have lugs itil and 182 (Fig. 7)which underlie the lever 177. Therefore, when either of the pins 16 or1&2 is raised by depression of the l and 2 value entry keys, the lugs101 and 132 also raise the lever 177 and the end pin 170 to fullyejected position.

A slightly dierent arrangement is provided for raising the end pin 170in response to depression of the keys 3 to "9. For this purpose, a link172 (Fig. 7) has pivotal connections at its opposite ends to a pair oflevers 173 and 174-. These two levers are pivotally connected to theset-up carriage Link 172 has six lobes 171 lying adjacent the sixselection hails 133-138. The bail 139 lies adjacent a lowerextension'173a of lever 173. lt will therefore he apparent that upondepression of one of the keys 3 to 9, the corresponding selectionbail133-139 will move toward the left and thus move link 172 toward theleft. At such time, an extension 175 on. the lever 174 will be movedcounterclockwise, and through contact with arm 176 on lever 177 willrock the lever 177 and the end pin 170 to its raised position.

The movement of the lever 177y as described above also releases a lockbar sitlfig. i) which locks the selected pin 161-169 and the end pin inraised position. An

il t) ear 180 on lever 177 normally lies in front of an extension 205ion the rightmost end of the lock bar 281 and holds the latter in theposition shown. Upon clockwise rocking movement of lever 177, the lockbar is released from ear 130.

Lock bar Zii is provided with arcuate slots which receive studs 12S,which it will be recalled, also serve to guide the up and down movementof the selection pins. ln the case of the lock bar, the studs 128 guidethe bar for 1 kwisc sliding movement about an imaginary centercoinciding with the main actuator shaft 210. Such movement is inresponse to the urgency of a spring (not shown).

A series of nine lugs 211 extend laterally from the lock bar and uponclockwise movement of the bar, one of the lugs moves under the shoulder194 of the raised value pin while the remaining eight lugs move over theshoulders 194 of the other value pins which have not been moved, thuslocking the pins in either their raised or their lower position, as thecase maybe. Meanwhile, the extension 20S of the lock bar moves under theear 5.80 on the end pin lever 177 and locks it in` raised position.

Each depression of a key to as well the 0, key also causes a singleorder escapernent of the selection set-up carriage to the next lowerorder of the storing Carriage. For this purpose, an escapement controllever 169 is pivotally mounted at 128 toy the setup carriage 120. Theupper rightmost end of lever 160 has a laterally bent extension 201which overles an escapernent pawl 202, pivotally mounted at 203 to theselection set-up carriage 120. The pawl is normally spring urged toengage between ordinally spaced teeth on an escapement rack 204 fixed tothe storing carriage 125. Upon depression of the "0 key and theclockwise movement of the zero bellcrank 149 the shift lever 160 isrocked clockwise whereupon its extension 201 moves the pawl 202 out ofengagement with the rack 204. At such time, a spring 20S, connected atone end to the set-up carriage and at its other end to the framework ofthe machine, moves the set-upcarriage towards the next lower order ofthe machine. If the operator has meanwhile released the "0 key, the pawl205 will engage the next tooth of the rack 204, thus completing theoneorder escapement, whereas if the operator rides the key, the ear onthe zero bellcrank 140, which is then held in clockwise position by thecontinued Vdepression of the 0 key, contacts the side of the next lowerorder shiftv control lever 'and holds the carriage in a half stepposition of escapement until the key is released to permit the remaining1/2 step of escapement and the reengagement of the -pawl with the rack.

The shift lever 160 is also rocked clockwise by the depression of thekeys l to 9 to cause escapement of the set-up carriage as follows. Whenthe end pin lever 177 is rocked clockwise, as previously described, ashoulder 192 on lever 177 depresses the lateral extension 201 on therightmost end of the shift control lever 160, thus initiating an ordinalescapement in the same manner as if the 0 key had been depressed. If theoperator rides any of the digital value entry keys this will hold itscorresponding bellcrank 141-149 in clockwise position and uponapproximately a half step of escapement of the setup carriage 120, thebellcrank will abut the side of a respective one of the next adjacentlower order value entry pins 161-169 thus holding the set-up carriage ina halfstep position until the key is released. Such release permits thebellcrank to return to initial position and the set-up carriage thencompletes its second half step of escapement whereupon the escapementpawl 202 re-engages the rack 204 to prevent further escapement of theset-up carriage. If the operator depresses a value entry key and quicklyreleases the key, the escapement of setup carriage is likewise limitedto a single order. In this case, the escapement pawl 202 is rockedcounterclockwise by ear 201 in the usual manner to initiate theescapement, and the ordinal shift lever 160, on which ear 201 is iixed,is locked in such position; hon over, pawl 202 escapes with the set-upcarriage ii and slides olf of ear 2M, thus permitting the pawl 2&2 toengage the next tooth of rack 204 and prevent further escapement of theset-up carriage.

This completes the value entering operation in the current order and theset-up carriage stands aligned with the next lower order of the storingcarriage where the next value entering operation may be made bydepressing the appropriate value entry ltey. This sequence of valueentering operations is followed in each order until the desired factoris entered into the storing carriage.

A plurality of indicator dials 184 (Fig. l) are provided for showing thevalues entered into the storing carriage. Such dials are conventionaland since they play no part in the present invention, no furtherdescription of the same is believed necessary. v

Digital actuating mechanism 'fhe digital actuating mechanism comprises aplurality ot' numeral wheel actuator clutches, one of which ispermanently associated with each numeral wheel of the accumulatorregister. Since the number of orders of actuator control pins in thestorage carriage is less than the number of orders of numeral wheelclutches, only certain groups of clutches are engaged and disengaged atany one time, depending both on the shifted position of the storingcarriage and also the number of ordinal values entered into the storingcarriage. The present invention, however, is not directly concerned withthe shifting mechanism for the storage carriage, and reference may behad to the previously mentioned patent for a description of one way inwhich a storing carriage is shifted relative to the numeral wheels.

Since all of the numeral wheel clutches are similar and the manner inwhich they are engaged and disengaged is the same, the description ofone such clutch will sutiice for all clutches.

An actuator clutch is generally designated at 231i in the left side viewshown in Fig. 2 and comprises in part, a ring gear 231 (Figs. 1 and 2)meshing with an idler 232 (Fig. l), the latter being entrained with agear 233 xed to the numeral wheel 234. The numeral wheels are drivenselected amounts by clutching and declutching the ring gear 231 from areversible, cyclically driven shaft 210 under the control of theselectively ejected pins ldl- 169 of the selection storing carriage.Each gear 2.3i (Fig. 2) is fixed to a supporting disc 235 which isfreely mounted upon the cyclically driven shaft 210. The gear 231 alsohas internal teeth 236 adapted for engagement by the tooth 237 of aclutch pawl 238. The tooth 237 extends through a slot 250 in a carrierplate 24th which is keyed to the cyclically driven shaft 210. The pawl23S is mounted for limited rocking movement on a pin 239 fixed to thecarrier plate 240, to rock the pawl tooth 237 into and out of engagementwith the internal gear 236 as follows.

A pair of meshing gear segments 241 and 242 are mounted for rockingmovement on pins 239 and 243 of the carrier plate 240. A torsion spring244 (Fig. 3) is anchored at one end to the carrier plate 24@ and at itsother end engages within a U-shaped slot 245 cut in the gear segment241, thus exerting a toggle action upon the segment and tending to holdthe same and its meshed gear segment 242 in either of two respectivelyrocked positions thereof. Normally, segments 241 and 242 stand in theposition shown in Fig. 2. Segment 242 carries a pin 246 adapted forengagement within a V-shaped slot 247 cut within the clutch pawl 238,and in the initial position of the parts as shown in Fig. 2, the pin 246is located in the extreme clockwise end of the slot 247, thus holdingpawl 238 in a counterclockwise position about its pivot 239 andtherefore holding the pawl tooth 237 out of engagement with the internalgear 236.

Qn the other hand, when gear segment 242 is rocked counterclockwiseabout its pivot 243 from the position shown in Figs. 2 and 3 to thatshown in Fig. 4, then the pin moves countercloclr'ivise to the oppositeend of slot 247 in pawl 238. The slot 247 is arcuate about the segmentpivot for a short distance and then assumes a straight line attitude.When pin 246 reaches the straight line portion of slot 247, the pawl 238is urged clockwise about its pivot 239 andthe pawl tooth 237 moves intoengagement with the internal teeth of ring gear 236 (Fig. 2). When pin246 (Fig. 3) reaches the straight line terminal position of slot 247,the pawl tooth is fully engaged with the ring gear at which time anyforce tending to disengage the tooth from the ring gear only drives pin246 more firmly against the limit of slot 247, thus holding the pawltooth and the ring gear engaged. With this condition of the parts, therotation of the carrier plate 240 results in similar rotation of gear236 and its associated numeral wheel. The return of the gear segment 242to the initial position shown in Fig. 2 causes disengagement of the pawltooth 237 from the internal gear 236, thus disenffaging the clutch 230.

During the cyclic rotation of shaft 210 and the carrier plate 240, thegear segments 241 and 242 are rocked under the control of an ejectedvalue pin 1611-169 and the end pin i7@ to cause engagement anddisengagement of the clutch as follows. Assume that a value of seven hasbeen entered into the storing carriage whereupon the No. 7 pin 167 andthe end pin 170 are raised to the dotted line positions shown in Fig. l.Since Fig. l is a right side View and Figs. 2-6 are left side views, thepositions of the end pin i7@ and the No. 7 pin 167 are reversed in thelatter views. Now, assume that the shaft 210 is turned once in aclockwise, or plus actuating, direction. Figs. 2 6 show progressivestages of operation of the clutch engagement and disengagement. in thisexample, the No. 7 pin 167 causes engagement of the actuator clutchwhereas the end pin 170 causes disengagement of the clutch.

With the parts in the initial position shown in Fig. 2, the actuatorclutch is disengaged and remains disengaged while the shaft 21@ and itsintegral carrier plate 240 move from the position shown in Fig. 2 tothat shown in Fig. 3. Segment 242 carries a pair of transversely bentears 251 and 252. Segment 241 carries a similar pair of ears 253 and 254which are bent in opposition to the ears 251 and 252 on segment 242. ltwill 'be recalled that the end pin 170 is laterally offset from thevalue pins ll-16E?, and since the respective ears of the two segments241 and 242 are bent in opposition to each other, each pin 167 and 170will cooperate with only one of the segments while the other segmentwill idly pass thereby.

Now, assuming that the carrier plate 240 is rotated from the positionshown in Fig. 3 to that shown in Fig. 4, such rotation carries the ear252 on segment 242 into engagement with the pin 167 and rocks thesegment 242 counterclockwise about its pivot 243, thus causingengagement of the actuator clutch, as previously described. Also, thecounterclockwise movement of segment 242 causes segment 241 to rockclockwise about its pivot 239 to the position shown in Fig. 4.

`Since the clutch remains engaged during the rotation of the disc 240from the position shown in Fig. 4 to that shown in Fig. 5, the clutchgear 231 (Fig. 2) advances the numeral wheel 234 by seven increments,the selected amount. Meanwhile, the segment 241, which is out of thepath of the pin 167, idly moves past that pin and also the segment 242which is out of the path of the end pin 7d, moves idly past the pin 170to the positions shown in Fig. 5. ln this position, the actuator clutchis still engaged but as the plate 240 continues to rotate clockwise tothe position shown in Fig. 6, the ear 253 on segment 241 contacts theend pin 170 and is rotated in a counterclockwise direction about itspivot 239. This imparts clockwise movement to segment 242 thus returningthe segments to their initial positions with 7 regard to plate 240 anddisengaging the actuator clutch, as previously explained. The actuatorclutch mechanism then rotates idly during the remaining clockwisemovement of plate 24@ to its initial full cycle position.

When the actuator clutch is rotated in a countcrclocltwise direction fora minus operation, the end pin f7@ serves as the clutch engagingcontrol, whereas the ejected value pin lol-169 controls thedisengagement of the actuator clutch. ln this case, the sequence ofoperations is opposite that described for plus operations and is bestobserved by starting with Fig. 6 and following back through Figs. 5, 4,and 3.

Assuming that the end pin 176 and a value pin 167 have been ejected, asshown in Fig. 6, and further assuming that the actuator clutch is beingrotated in a counterclockwise direction for a minus operation, the ear254 on segment 241 contacts the end pin i7@ and is rocked clockwise asshown in Fig. 5. The segment 241 in turn rocks segment 242 in acounterclockwise direction to effect engagement of the clutch.

Then, as seen in Fig. 4, the ear 255. on segment 242 is shown asapproaching the pin $.67. Upon contacting pin 167, the segment 242 isreturned in a clockwise direction to its initial position shown in Fig.3, thus disengaging the actuator clutch. then rotates idly during theremaining counterclockwise rotation of plate 24@ to the initial fullcycle position shown in Fig. 2.

No specific type of tens carry mechanism has been disclosed in thepresent machine since the choice of such a mechanism is not pertinent tothe present invention; however, a gear 255 (Fig. l) is shown fortransmitting the tens carry drive to the numeral wheel, and this gear255 may be driven by a tens carry mechanism of the type disclosed in theReynolds patent application Serial Numu ber 327,104, tiled December 20,1952, now `Patent No. 2,694,524, issued Nov. 16, 1954, in which the tenscarry mechanism operates simultaneously in all orders of the register. Atens carry phase follows each actuating phase and since the inventionhas been disclosed in a type of machine in which the actuators arereversible for plus and minus drives of actuation, two tens carry phasesare provided, in each actuating cycle, as is common in this type ofmachine. Therefore, the active tens carry phase which follows plusdigitation, becomes an idle tens carry phase which precedes subtractivedigitation, and the tens carry phase which follows subtractivedigitation becomes an idle phase which precedes plus digitation. Anumeral wheel detent is described in the following paragraph and whichdetent is enabled to prevent overthrow of the numeral wheel at the endof both digital actuation and tens carry actuation. With reference tothe operation of the detent during the tens carry phase, it will benoted that for convenience in design of mechanisms, the detent will beoperated during both the idle and active tens carry phases and,therefore, the detent will partake of an idle operation during the idletens carry phase as well as an active operation during the active tenscarry phase.

Non-overthrow detent A detent 24S (Figs. 3-6) is provided in each orderof the accumulator register to engage a gear 249, which is integral withthe idler gear 232 (Fig. l), and prevent overthrow of the numeral wheelboth upon disengago ment of the actuator clutch and also aft-er any tenscarry increment of drive. Referring iirst to the operation the detentupon disengagement of the numeral wheel clutch, it will be noted thatsince all of the numeral wheel clutches are disengaged at the same timeby the end pins 170 during plus operations, a cyclically operable devicemay be provided to move all of the noncverthrow detents to activeposition at the same time. During a minus operation, however, thedisengagement of the various clutches is under control of the actuatorclutch control pins 161-169 which cause disengagement at vari- Theclutch mechanism able times during a cycle of actuation, and thereforethe operation of the detents is under direct control of the actuatorclutch pawls, i. e., when a clutch pawl moves to clutch disengagingposition, it motivates devices to move the non-overthrow pawl intoengagement with the numeral wheel gear train and prevent overthrow ofthe numeral wheel.

The detent 248 is loosely keyed to a shaft 256 and is normally helddisengaged from gear 249 by a spring Shaft 256 is rocked clockwise toengage the detent with the gear 249 by a cam 263 (Fig. 8) and followerrfhe cam is mounted on the main actuator drive shaft 216 and has threelobes 265, 266 and 267, extending beyond its periphery. The follower 264is fixed to shaft the arrangement is such that shaft 256 is rocked in aclockwise direction and detent 248 (Fig. 3) is rocked into engagementwith gear 249 by the cam lobes at three different times during eachcycle of actuation, these rocking movements occurring during each of thetwo tens carry phases and once during the digital actuating phase.

During a plus actuation, the actuator clutch mechanism is rotated in aclockwise direction to the position shown in Fig. 3 yand during thefirst portion of such rotation, the clutch mechanism moves through anidle tens phase. At the beginning of this phase, the detent 248 is idlyrocked in to engage the gear 249 and then is rocked out again by camlobe 265 (Fig. 8). Shortly thereafter, an arcuate rail 258 (Fig. 3),carried by the clutch pawl 238, engages a roller 259 carried by thelower extending arm of detent 248. At this time, the clutch pawl 238 isheld in a counter-clockwise disengaged position about its pivot 239, aspreviously explained, and the arrangement is such that the rail idlyholds the detent in the position shown until the clutch pawl movesclockwise about its pivot 239 to the clutch engaging position shown inFig. 4. At such time, the rail 258 moves toward the center of the clutchmechanism, thus permitting the spring 257 to rock the detent 248 awayfrom gear 249. Thus, when the clutch is iirst engaged, the detent isautomatically disengaged from the gear 249.

The clutch mechanism continues to rotate and the clutch is subsequentlydisengaged as shown in Fig. 6. In this case, the end pin 170 causesdisengagement of the clutch and since the disengagement of all clutchesby their pins 70 occurs at the same time, all of the detents 248 aresimultaneously rocked clockwise by the cam lobe 267 (Fig. 8) which rocksthe detent support shaft 256. Shortly thereafter, the cam lobe movesfrom under the follower arm on shaft 256 and permits the detent toreturn to its initial counterclockwise position before the active tenscarry phase is begun. Then again, after the tens carry phase iscompleted, another lobe 266 rocks the detent in and out of engagementwith the gear 249 to prevent overthrow of the numeral wheel after tenscarry. This completes the operation of the non-overthrow means during aplus cycle of actuation.

When the actuator clutch mechanism is rotated in a counterclockwisedirection for a subtractive actuating operation, the machine first goesthrough an idle tens carry i phase, and. as previously described, thedetent 248 is momentarily rocked into and then out of engagement withthe gear 249 by cam lobe 266 (Fig. 8). After the tens carry phase iscompleted, vthe cam lobe 267 idly rocks the detent into and out ofengagement with its gear. Then the clutch is engaged by the end pin 170as .the clutch rotates from the position shown in Fig. 6 to that shownin Fig. 5. During such engagement, the clutch pawl is in a clockwiseposition relative to its pivot 239 and therefore, the rail 258 on theclutch pawl is also in its clockwise position, thus permitting thespring 257 to hold the detent out of engagement with gear 249. Thisrelationship is maintained until the clutch is disengaged as shown inFig. 3, at which time the clutch pawl 238 and rail 258 movecounterclockwise about the pivot 239. The rail then contacts either oneor both of the two rollers 259, 260,

on the lower arm of the detent 248 and rocks the latter clockwise intothe gear 249. After the rail 258 passes from beneath the rollers, thedetent is spring urged in a counterclockwise direction out of engagementwith the gear 249. Shortly thereafter, the active tens carry operyationtakes place after which lobe 265 on the detent control cam again rocksthe detent 248 into and out of engagement with the gear 249.

After the desired number of cycles of actuation have been completed, theactuator control pins and the end pins of the storing carriage arereturned to initial position merely by returning the locking bars 281(Fig. l) in each order to their initial counterclockwise positions wherethey are locked by engagement of the ear 180 on the end lever 177 withthe projection 208 of the lock bar. This releases the pins 161-169 andthe end lever 170 to the urgency of their respective springs for returnmovement to initial positions. Mechanisms for moving the lock bars toinitial positions are not shown here but are well known in the art. Forexample, a transverse bail, such as th-at shown in cross section at 261,may be provided which is cyclically or manually operable to movedownwardly and return the released lock bars to their initial positions.

The non-overthrow detent mechanism disclosed herein forms the subjectmatter of a divisional patent application Serial No. 707,316.

We claim:

l. In a calculating machine having a register comprising a plurality ofordinally arranged numeral wheels and a value entering mechanism; aclutch permanently associated with each numeral wheel, each clutchincluding a drive element, a driven element, and connecting meansbetween the ydrive and the driven element, and two control devicescarried by said drive element operable under control of the valueentering mechanism to cause said means to connect and disconnect thedrive and driven elements.

2. In a calculating machine having a value entering mechanism and anumeral wheel register, respective clutches for advancingeach numeralwheel in accordance with a pre-selected value, each clutch comprising acyclically operable drive element, a driven element, and a membercarried by the drive element adapted to engage with and drive the drivenelement; the combination of, a rst device for moving said member toclutch engaging position, a second device for moving said member toclutch disengaging position, and means controlled by said value enteringmechanism to cause the operation of the first and second devices.

3. A calculating machine including a register comprising a plurality ofordinally arranged numeral wheels, a value entering mechanism comprisinga keyboard and a plural order pin carriage, a plurality of valuerepresentative pins in each order of the pin carriage, any one of whichis selectively movable from an inactive to an active position undercontrol of the keyboard, another pin in each order movable from aninactive to an active position under control of the'keyboard, ordinallyarranged clutches for the numeral wheels each clutch comprising a driveelement, a driven'element and a connecting means between the drive anddriven elements, and control devices carried by the drive elementoperable by said two active pins to cause said means to connect anddisconnect the drive and driven clutch elements.

4. A calculating machine including a numeral wheel register, a valueentering mechanism comprising a keyboard and a plural order pincarriage, each order of the pin carriage including a plurality of valuerepresentative pins movable from an inactive to an active position undercontrol of the keyboard, another pin in each order movable from aninactive to an active position under control of the keyboard, reversibleactuating means for the numeral wheels including numeral wheel clutcheseach comprising a drive element, a driven element, and connecting meansfor causing the drive element to drive the driven element, contro!devices carried by the drive element operable by an active valuerepresentative pin during rotation of the clutch in one direction tocause said connecting means to connect the drive and driven clutchelements, and operable by said other pin during rotation of the clutchin the reverse direction to cause said connecting means to connect thedrive and driven clutch elements.

5. A calculating machine according to claim 4 in which the active valuerepresentative pinvcauses said devices to move the connecting means to aclutch disconnecting position during the reverse rotation of the clutch,and in which the other pin causes said devices to move said means toclutch disconnecting position during forward rotation of the clutch.

6. A calculating machine having a numeral wheel register and valueentering mechanism including a keyboard and a plural order pin carriagecomprising in each order a plurality of pins, two of which are movedfrom an inactive to an active position upon depression of a valueentering key, a numeral wheel clutch including a drive element, a drivenelement, land a -member movable from a first position to a secondposition to connect the drive and driven elements, and movable from thesecond to the first position to disconnect the drive and drivenelements, and means operable under control of said two pins to move saidmember to its respective connecting and disconnecting positions.

7. A calculating machine according to claim 6 in which the drive elementof the clutch is operable in either of two directions for positive landnegative numeral wheel actuation, respectively, and in which the tworespective pins which control the engagement and disengagement of theclutch during positive numeral wheel actuation reverse their functionsduring negative numeral wheel actuation and control, respectively, thedisengagement and engagement of the clutch.

8. A calculating machine according to claim 6 in which the movablemember is operable by one of a pair of meshing gear segments carried bythe drive element, the gear segments being rocked to move the member toits connecting position by the first one of said two pins and rocked toits disconnecting position by the second one of said two pins.

9. A calculating machine having a register including numeral wheels, arespective clutch associated with each numeral wheel, a value entrykeyboard, a plural order pin carriage including in each order thereof aplurality of pins, means responsive to depression of a value entry keyfor moving two pins in a respective order from a normally inactiveposition to an active position, and means controlled by said two pins tocause engagement and disengagement, respectively, of the numeral wheelclutch.

l0. In a calculating machine having a register including ordinallyarranged numeral wheels, ordinally arranged actuator clutches therefor,and selectively settable means for controlling said actuator clutches,the actuator clutches comprising in each order a driven element, acyclically driven carrier upon which a clutch `pawl is freely pivoted,and means for controlling the engagement and disengagement of said pawlwith said driven element, including a pair of meshing gear segments eachfreely pivoted on said carrier for rocking movement from a first extremeposition to a second extreme position, a pin iixed to one of said gearsegments engaging within a slot in said pawl Iand operable in the rstextreme rocked position of said segments to hold said pawl out ofengagement with the driven element and operable in the second extremerocked position to hold said pawl in engagement with the element, andmeans operable in response to the cyclic movement of the carrier andunder control of said selectively settable means to cause the rockingmovements of the gear segments.

(References ou following page) References Cited in the le of this patentUNITED `STATES PATENTS Avery Mar. 3, 1,936 Rast :May 4, 1937 Lake et al.Sept. 7, 1943 Avery Oct. 30, 1945 12 Schneider Feb.- 12, 1946. Beattieet a1. Mar. 14, y1950 Brand .et al. Apr. 4, 1950 Gourdon Sept. 18, 1951FOREIGN PATENTS Great Britain Nov. 18, 1948

